Cost doesn't determine quality of a happy life. I think a quality of life will keep = means that I have basic food, clothing and shelter.
Of course, if I am poor, my life is difficult to live but the rich is not all = always  happy.
A few weeks ago, I saw a documentary about 'money',
there comes a man who successes on the stock, everyone think he will be very happy.
But he says ' I'm always worried and nervous to lost all money."
On the contrary, an ordinary office worker satisfy himself = is satisfied with his life.
He has less money than man who successes = succedded  on the stock,but he feel more happy = feels happier.
So cost or money can make our quality of life perfectly = does not make a quality life,
We can live a happy life if we have the higher satisfaction.